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| <tr><td width=20><td><b>COLOR(3)</b><td align=right><b>COLOR(3)</b> |
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| <p><font size=+1><b>NAME </b></font><br> |
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| cmap2rgb, cmap2rgba, rgb2cmap – colors and color maps<br> |
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| <p><font size=+1><b>SYNOPSIS </b></font><br> |
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| <tt><font size=+1>#include <u.h><br> |
| #include <libc.h><br> |
| #include <draw.h> |
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| <tt><font size=+1>int rgb2cmap(int red, int green, int blue) |
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| </font></tt> |
| <tt><font size=+1>int cmap2rgb(int col) |
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| </font></tt> |
| <tt><font size=+1>int cmap2rgba(int col)<br> |
| </font></tt> |
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| <p><font size=+1><b>DESCRIPTION </b></font><br> |
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| These routines convert between ‘true color’ red/green/blue triples |
| and the Plan 9 color map. See <a href="../man7/color.html"><i>color</i>(7)</a> for a description of RGBV, |
| the standard color map. |
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| <i>Rgb2cmap</i> takes a trio of color values, scaled from 0 (no intensity) |
| to 255 (full intensity), and returns the index of the color in |
| RGBV closest to that represented by those values. |
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| <i>Cmap2rgb</i> decomposes the color of RGBV index <i>col</i> and returns a |
| 24-bit integer with the low 8 bits representing the blue value, |
| the next 8 representing green, and the next 8 representing red. |
| <i>Cmap2rgba</i> decomposes the color of RGBV index <i>col</i> and returns a |
| 32-bit integer with the low 8 bits representing an alpha |
| value, defined to be 255, and the next 8 representing blue, then |
| green, then red, as for <i>cmap2rgba</i> shifted up 8 bits. This 32-bit |
| representation is the format used by <a href="../man3/draw.html"><i>draw</i>(3)</a> and <a href="../man3/memdraw.html"><i>memdraw</i>(3)</a> library |
| routines that take colors as arguments.<br> |
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| <p><font size=+1><b>SOURCE </b></font><br> |
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| <tt><font size=+1>/usr/local/plan9/src/libdraw<br> |
| </font></tt> |
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| <p><font size=+1><b>SEE ALSO </b></font><br> |
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| <a href="../man3/graphics.html"><i>graphics</i>(3)</a>, <a href="../man3/allocimage.html"><i>allocimage</i>(3)</a>, <a href="../man3/draw.html"><i>draw</i>(3)</a>, <a href="../man7/image.html"><i>image</i>(7)</a>, <a href="../man7/color.html"><i>color</i>(7)</a><br> |
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